1. Field of the Invention
The invention relates to methods and systems for detection of subterranean anomalies such as voids and leaks by the use of infrared thermography and, more particularly, to methods and system for using infrared thermography together with ground penetrating radar to map subterranean leakage voids and to repair such voids and terminate such leakage in a very highly accurate, reliable, rapid and cost-effective manner.
2. Related Art
The present inventor is the patentee of Weil U.S. Pat. No. 4,910,593 issued Mar. 20, 1990, entitled System for Geological Defect Detection Utilizing Composite Video-Infrared Thermography, hereinafter referred to as the “Entech INSITE I System” or, more simply herein, the “Entech System.” This patent, which is herein incorporated by reference, discloses a selectively mobile system with an infrared (“IR”) scanner and video camera having a common area of focus and apparatus for detecting location permits detection of subterranean geological anomalies. Infrared and visual images are simultaneously successively recorded on videotape together with related location data and other relevant information. Video recorded infrared, video and location data are selectively captured on successive frames. Such frames are recorded for further analysis such as for determining the location and extent of subsurface anomalies such as leaks. That system, which is especially useful for mapping such anomalies along a route of travel, as across bridges, highways and other traffic surfaces such as paved surfaces or for examining surfaces that extend over elongated passages such as buried sewer and water lines, does not involve the additional use of ground penetrating radar, nor does it disclose methods for repair of anomalies detected by the use of the patented system. That system has advantageously led to the development of a pipeline leak and erosion void sensing and non-destructive testing.
3. Background Information
Most underground conduits or pipelines, whether they contain oil, chemicals, water, steam, gas or sewage, have a design life of 25 to 50 years, and when they begin to fail, they do so slowly at first through defective construction joints, corrosion and small cracks, and gradually progress to a catastrophic ending. This disastrous failure can be expensive in terms of both dollars and lives. But this scenario can be avoided. Planned maintenance can extend the life of all types of pipelines almost indefinitely, and regular testing of pipelines form the basis of economically viable restoration. In order for any testing technique to have widespread advantage, it needs to have the following qualities:                It must be accurate.        It must be non-invasive and non-destructive.        It must be able to inspect large areas and localized areas.        It must be efficient in terms of both labor and equipment.        It must be economical.        It should not be obtrusive to the surrounding environment.        It should not inconvenience the pipeline's users.        
Chemical refineries, in particular, contain hundreds of miles of buried pipelines. In addition to a typical proliferation of oil and gas pipelines, such refineries have dozens of other types of pipelines such as sewer, water, steam, condensate, firewater and chemical pipelines that are often part of refinery support systems. Their integrity is crucial to the economic well-being and safety of these facilities.
Heretofore, project, typical buried sewer pipelines have been inspected by using closed circuit television, ultrasonic and/or sonic listening devices, or traveling inspection devices (“pigs”). None of these work satisfactorily on a refinery pipelines or sewers because: 1) Such lines may range in size from 1″ to 72″ diameter, for example; 2) They may be either gravity and pressurized systems; 3) They typically are buried beneath major pieces of refining equipment and mixed in with hundreds of other types of pipelines; and 4) Nearby pipelines and equipment produce prodigious amounts of auditory noise which interferes with testing. The lack of any accurate method or system of investigating the buried conduits, pipelines or sewer lines, for example, can lead to many unknowns that can significantly increase the rehabilitation costs of the traditional excavation and concrete encasement methods of repair.
Since 1998, the U.S. Environmental Protection Agency (EPA) has focused on refinery sewers as major ground and water pollution sources. In the wake of enforcement legal proceedings, refineries have increased inducement to inspect these sewer lines and other pipelines for leaks and to repair contamination sources therefrom.